APPLIED CLAY SCIENCE
·
2017
·
IF 3.101
Tao Wu,Zhifen Wang,Hai Wang,Zhiqiang Zhang,Luc R. Van Loon
The through-diffusion method was employed to investigate the effect of the salt concentration on the diffusion behaviour of Re(VII) and Se(IV) in compacted bentonite . The accessible porosity , ε acc , of Re(VII) increased from 0.25 to 0.38 with an increase of the ionic strength from 0.1 to 1.0 mol/L. The dependency of the accessible porosity ε acc on the salt concentration could be described approximately by a first-order decay exponential function. The interlayer porosity of GMZ bentonite was 21% of the total porosity at a bulk dry density of 1600 kg/m 3 at 12 °C. The D e values of Re(VII) and Se(IV) increased from 2.6 × 10 − 11 to 6.1 × 10 − 11 m 2 /s and from 1.6 × 10 − 11 to 4.7 × 10 − 11 m 2 /s in GMZ bentonite with an increase of the ionic strength from 0.1 to 1.0 mol/L, respectively. In the case of Se(IV), the adsorption showed a different ionic strength dependency in GMZ bentonite and montmorillonite . The ionic strength has no significant effect on the adsorption (K d = 1.8 × 10 − 4 m 3 /kg) on GMZ bentonite, indicating the formation of inner-sphere surface complexes. In the case of synthetic montmorillonite, the K d values increased with increasing ionic strength. This can be explained by the fact that the electric potential of surface sites becomes less negative with increasing ionic strength resulting in an increase in the adsorption of Se(IV) at a pH above the point of zero salt effect (PZSE). The D e values of both Re(VII) and Se(IV) increased with increasing salt concentration. Both anions are totally excluded from the interlayer space and partially from the diffuse double layer. Ionic strength alters the effective diffusion coefficient of anions by controlling the thickness of the diffuse double layer. Anion diffusion data from the literature (effective and apparent diffusion coefficients) were satisfactorily evaluated by Archie's relation.
研究领域:
环境科学
·
地球化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Xianquan Cai,Linghao Kong,Xingyun Hu,Xianjia Peng
Strongly acidic wastewater generated from the molybdenum and copper smelting process is of great value for recycling sulfuric acid and valuable metals, such as rhenium (Re). Herein, a high Re(VII) (HReO 4 ) recovery efficiency of 99% within 35 min from strongly acidic wastewater was successfully achieved by using sulphide coupled with ultraviolet (UV) light, and soluble Re(VII) precipitated as Re 2 S 7 in this process. Mechanistic experiments showed that the intermediate Re-S species (i.e., HReO 3 S) was the dominant limitation responsible for Re(VII) precipitation in the dark, and UV irradiation dramatically accelerated the generation and conversion of HReO 3 S by inducing the formation of HS• and H•. The H• produced from the photodissociation of H 2 S promoted HReO 4 transformation to H 2 ReO 4 •, which rapidly reacted with HS• to produce HReO 3 S, accelerating the conversion of HReO 4 . The radical-induced acceleration can also take place during the HReO 3 S conversion by slowly introducing H 2 S into the strongly acidic wastewater to continuously produce H• and HS•. This work offers an insight into the improvement of Re(VII) recovery by UV light, which can be potentially applied into resource recovery from strongly acidic wastewater.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2012
·Vol. 88
·期 3
·437-443
·
IF 2.168
Min Jia,Hongmin Cui,Weiqun Jin,Lili Zhu,Yu Liu,Ji Chen
BACKGROUND: Rhenium is a rare and valuable metal coexisting with molybdenum in molybdenite and sulfide copper ores and is hard to separate. Methods such as solvent extraction, ion exchange, adsorption, precipitation, etc. have been used to separate and purify Re(VII), and resin ion exchange has been widely investigated and used owing to its convenient operation and relatively low-cost. The main challenge comes from the preparation of resins having high performance and stability. In an earlier study, an N-methylimidazolium functionalized strong basic anion exchange resin was successfully synthesized and used for Cr(IV) extraction. This paper, reports on further synthesis and application of this resin for adsorption and separation of Re(VII) and Mo(VI), especially from copper arsenic filter cake. RESULTS: At pH 6.25, Re(VII) and Mo(VI) can be effectively separated with the N-methylimidazolium functionalized strong basic anion exchange resin, giving a Re(VII) recovery of up to 93.3%, but only 5.1% for Mo(VI). When using the copper arsenic filter cake sample 89.1% Re(VII) recovery was achieved. CONCLUSION: The N-methylimidazolium functionalized strong basic anion exchange resin exhibited high selectivity and recovery for Re(VII) in a mixed system. © 2012 Society of Chemical Industry
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2024
·Vol. 333
·期 5
·2273-2280
·
IF 1.5
Zhang Hui,Wang Ju,Wu Wangsuo,Luo Mingbao,Hua Rong,Zhou Zhichao,Ling Hui
This paper presents the first laboratory-based, simultaneous diffusion experiments of Re(VII) and Se(IV) in Tamusu (TMS) clay, using the capillary method. We determined diffusion coefficients ( D a ) and adsorption values ( K d ) for these nuclides under varying clay compaction densities, solution pH values, ionic strengths, and in the presence of humic acid (HA). The results indicated rapid acquisition of diffusion data, the D a values predominantly ranging from 10 −9 m 2 /s to 10 −10 m 2 /s, and weak adsorption for both Re(VII) and Se(IV). While the presence of HA augmented the D a and K d values for Re(VII) and Se(IV) diffusion in clay, these values did not exhibit significant alterations in response to increasing HA concentrations.
研究领域:
环境科学
·
地质学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2016
·
IF 2.586
Tao Wu,Zhifen Wang,Qingmei Li,Guoxiang Pan,Jinying Li,Luc R. Van Loon
In order to understand the diffusion properties of anionic radionuclides (RN) in bentonite in the presence of organic compounds with chelating and reducing properties, the effect of humic acid (HA), citrate, oxalate and formate on Re(VII) diffusion was investigated by a through-diffusion method under different pH (pH 7.0 and 10.0) and temperature conditions (10–65 °C). When the molar ratio of oxalate to Re(VII) was higher than 1:1, the accumulated mass and flux were observed to decrease drastically as a function of time. It can be explained by photocatalytic impact of Fe(III) on the reduction of Re(VII) to insoluble Re(IV) by oxalate. Thus, the diffusion of Re(VII) was also observed to decrease in the presence of minor citrate, oxalate and formate. Effective diffusion coefficient (D e ) values decreased from 8.7 × 10 − 11 m 2 /s to (5.1–5.9) × 10 − 11 m 2 /s. In contrast, HA had no significant impact on Re(VII) diffusion. The D e values of 1.54 × 10 − 11 and 6.5 × 10 − 12 m 2 /s were obtained at pH 7.0 and 10.0, respectively. HA thus neither has an effect on the speciation of Re(VII) nor does it change the charge of the surface. The latter is probably due to the fact that HA preferentially interacts with the aluminol sites of the montmorillonite edges without changing the zeta potential of the surface. The dependence of D e of Re(VII) on temperature in the absence and presence of citrate or formate was described by the Arrhenius equation . The activation energy, E a , was in the range of (20.7–25.1) kJ/mol, demonstrating that Re(VII) diffusion followed a pore water diffusion model .
研究领域:
环境科学
·
放射化学
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产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2019
·Vol. 321
·期 1
·235-242
·
IF 1.186
Zu Jianhua,Fu Lingxiao,Tang Fangdong,He Linfeng
A new pyridyl anion exchange resin (PS-N) was synthesized by chloroacetylation and quaternization on the polystyrene-divinylbenzene microspheres (PS) and was characterized by FT-IR, TGA, and X-ray photoelectron spectroscopy. PS-N was applied to study the removal of Re(VII), a chemical analogue of 99 Tc, to investigate the effect of solution acidity, resin dose and contact time on the adsorption efficiency. The adsorption process corresponded with the Langmuir isotherm model and matches well with pseudo-second-order kinetics. Based on the adsorption results of Re(VII), the adsorption efficiency of 99 Tc was examined to be 99.5% at optimum conditions.
研究领域:
环境科学
·
核化学与放射化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2016
·Vol. 311
·期 1
·655-661
·
IF 0.983
Wang Zhifen,Zhang Jianying,Chen Jiang,Zhang Zhiqiang,Zheng Qing,Li Jinying,Wu Tao
A through-diffusion method was used to investigate the Re(VII) (as a surrogate to 99 Tc(VII)) diffusion in compacted illite-, hematite- and limonite-montmorillonite mixtures. The effective diffusion coefficient D
e values were in the range of (4.29–6.71) × 10 −11 m 2 /s at pH 3.0 and (3.44–5.72) × 10 −11 m 2 /s at pH 9.0, respectively. Compared to montmorillonite, both D
e and α values enhanced at least three-folds in montmorillonite mixtures, indicating that the impurities changed the diffusion path. Interestingly, the K
d values of (0.63–3.94) × 10 −4 kg/m 3 were found in montmorillonite mixtures. However, the change of D
a value was less than two-folds, indicating that the illitization and iron corrosion of a back-fill material had no obvious influence on Re(VII) diffusion velocity.
研究领域:
环境科学
·
放射性废物管理
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2020
·Vol. 326
·期 1
·445-454
·
IF 1.137
Liu Fuping,Hua Rong,Zhang Feng,Liu Heng,Lee Chuan-Pin,Liu Hesheng,Xu Bin
A new strong base anion exchange resin (LSL-1) was synthesized by grafting trimethylamine groups onto polystyrene-divinylbenzene microspheres and used for the selective recovery of Re(VII) from U(VI)-containing effluent. The morphology and structural properties of LSL-1 were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The adsorption mechanism is discussed. In both batch and column experiments, LSL-1 showed excellent enrichment capacity for Re(VII). This study demonstrates a new approach for the separation and recovery of Re(VII) from U(VI)-containing effluent by using amino-modified polystyrene-divinylbenzene microspheres.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）